Fluid-gage.



M. MARTIN.

FLUID GAGE.

APPLICATION FILED APB..13, 1907.

Patented Nov. 10, 1908.

UNITED STATES PATENT oEEIoE.

MORRIS MARTIN, OF BOSTON, MASSACHUSETTS.

FLUID-GAGE. I

The invention to be herein described is intended as an improvement onthe class of gage represented in United States Patents No. 794,675, andNo. 7 94,67 6 heretofore granted to me.

In the gages described in said patents, a magnetized needle iscontrolled as to its movements by a magnet which is rotated by orthrough a float which rises and falls due to differences of level offluid in a tank, the magnetized needle being always free to follow themovements of the magnet.

In the use of a gage of this kind, it has been found very desirable tobe able to detect whether or not gasolene in the tank to which the gageis applied is tampered with; 2'. 6., abstracted from the tank; and alsoit is of importance to many owners of automo-' biles to be able to tellwhether or not his car has been used without his consent. Consequently Ihave invented what I call a detective gage that I shall hereinafterfully describe, the magnetic needle of said gage being readily lockedwhenever desired. The needle may be locked in the act of detaching theneedle carrier from the gage head, and the needle automatically lockedis held in just the position in which it was held by the magnet underthe control of the float resting on the gasolene at the time when theneedle was locked, and when the needle is again unlocked, as itmay bewhen the needle carrier is again applied to the head of the gage, if anychange in fluid conditions in the tank has taken place, the magneticneedle, on its release, will immediately be moved into alinement withthe magnet and indicate such change, thus immediately showing whether ornot the gasolene in the tank has been tampered with, or the machine hasbeen run, and it will be impossible to exhaust part of the gasolene andthen refill the tank to meet the exact conditions of the magneticpointer.

I believe that I am the first to construct a magnetic gage wherein themagnetic needle may be instantly locked and remain locked untilreleased, or a gage wherein the needle- Specification 01' LettersPatent.

Application filed April 13, 1907. Serial No. 368,050.

Patented Nov. 10, 1908.

carrying part of the ga e may be readily removed from the head 0% thegage closing the opening into a tank, the act of removing the needlecarrier locking the magnetic needle in the position it occupied whencontrolled by the magnet, and I desire to claim this feature broadly inwhatever form, as it will be understood that numerous devices differingin construction may be employed for locking the magnetic needle and yetbe within the scope of my invention.

Figure l in section represents a gage in which I have embodied myinvention'in one of the best forms now known to me; Fig. 2 is a planview ofthe top of the gage; Fig. 3 is a plan view of the needle carrierwith the dial removed; Fig. 4 is a detail of the magnetized needle andits tubular shank; Fig. 5 in plan view shows'a modification of myinvention with the dial removed and the needle locked; Fig. 6 is asimilar view with the needle unlocked; Fig. 7 is a side elevation of thegage head, and Fig. 8 is a section of the head of my modified gage withthe dial and needle in plan, the needle being unlocked.

Referring to the drawing, A represents the gage head, the latter in itspresent form being gas 'andfluid tight, it having screw threads A bywhich to screw the head of the gage into any suitable bushing secured toa tank. The gage head has a rim A provided with a slot A, and risingfrom the top of the gage head is a releasing device (1 shown as apointed stud.

The magnetized needle I) has, as shown, a tubular shank b that is fittedover and surrounds a pivot b rising from the bottom of a needle carrier0, the latter, as herein shown, being represented as a metal box havinga hole b to be entered by the releasing device a of the gage head. Theneedle carrier when in its operative position is fitted within the rim Aand at such time the releasing device enters the hole b of said carrier.The needle shoulder upon which is laid a piece of glass i d, and abovethe glass theinncr wall of the needle carrier is provided with anothergroove for the reception of a locking ring 3 or wire to maintain theglass in its operatlve position.

The magnetic needle is free to revolve in the space between the dial andthe under side of the glass, and said needle is so revolved as themagnet is rotated as will be described, the arrow head of the magneticneedle moving over the gradations of the dial indicatin the amount ofgasolene or other fluid in t e tank with which the gage is to be used. g

The magnet m is mounted u on the upper end of a shaft (5. surrounde by ahollow metal float d which may be such as fully described in UnitedStates Patent No. 794,675, the float resting on the surface of the fluidin the tank and in its rising and falling movements due to variations inthe depth of fluid in the tank turning the shaft and magnet.

I have herein shown the shaft as without a twist, and the float asprovided with a pin e that may enter a spiral slot in a tube E, asprovided for in the patent hereinbefore referred to, but instead ofemploying a tube with a spiral slot, I may employ a tube with a straightslot, and twist the shaft as in United States Patent No. 7 SL677 so thatas the float rises and falls, the shaft and magnet will be rotated, orinstead of the tube I may use any other usual floatguiding means, suchas a guide rod or rods. I prefer, however, to use a tube within whichthe float will rise and fall, yet this invention is not limited to theuse of a tube, as the float may be guided in any other usual orcustomary manner without departing from my invention.

The needle carrier is shown as provided with a stem t having a ring 5such as usually employed in connection with a watch to handle the same,and I contemplate locking the needle carrier in position, if need be, onthe head, so that a thief may not remove the needle carrier if anautomobile containing the gage should be left in the street. To effectthis looking, I extend from the head of the gage a projection 6 providedwith a hole over WlllCh the ring of the needle carrier is laid, and theninsert the hasp of a small padlock 7 in the hole in said projection. The

. locking device for the needle carrier is shown as comprising a springf having two fingers 8, 9, said fingers being of a length .to cross thepivot sustaining the magnetlc needle, and also being so arran ed thatthe releasing device, when the needle carrier is in its operativeposition, will stand between the two arms of the locking device and holdsaid device in its inoperative position, leaving the magnetized needlefree to be turned by the magnet.

Now viewing Fig. 1 let it be supposed that the owner of a car, orwhoever is running the same and has a right to do so, stops his car in ashelter or garage, he will immediately pick oil or remove the needlecarrier from the head of the gage, and in so' same in just the positionthat it" occupied due to the holding action of the magnet m. The

needle carrier may be put in the pocket, and whenever the car is to beagain started, the needle carrier will be applied to the head of thegage, and instantly the releasing device will enter between and open thelocking I device, thus releasing the shank of the magnetic needle sothat it will immediately change its position to correspond with theposition of the magnet, which as before stated, is always controlled bythe quantity of gasolene or other fluid in the tank,-if the amount offluid in the tank differs at all from what was in the tank when theneedlecarrier was removed. The magnetic needle will instantly turn inone or the other direction to indicate any change in the amount ofgasolene or other fluid in the tank.

In Figs. 5 to 8 showing a modification of my invention, I have providedfor locking the magnetized needle whenever desired in any positionwhereit may be held by the magnet so that it will not be turned by the magnetwhile so locked, said means being efiective to lock the needle withoutremoving the same from the head of the gage. The locking means in themodification comprises a spring 9 having two arms, the free ends ofwhich are shaped as best shown in Figs. 5 and 6, one end of the springbeing inserted in a recess cut in a shoulder 9' inside the curb A of thehead A. The head has a hole 10 that receives a releasing device shown asa stem it having a head it and as provided with a ring ,5, the releasingdevice when 00- cupying the position shown in Fig. 6, where the headoccupies a position between the free ends of the spring, spreading thespring so as to release the shank I) of the needle it, in the modifiedconstruction, fitting loosely a pivot 12 mounted in the head. To lookthe needle it is only necessary to withdraw the releasing device fromtheposition shown in Fig. 6 into the position shown in Fig. 5 when thespring acting normally closes itself upon the shank of the needle. Ifdesired,

the releasing device may be entirely withdrawn from the head through thehole 10 anddput into the pocket to be used when desire In using themodification, if the locking device occupies the position shown in Fig.

6, the magnetic needle will obey the magnet and follow the same in allits movements due to variations of gasolene in the tank, and if the carhaving the gage is put up anywhere over night, or when gasoleneconditions are liable to be changed, the releasing device may be whollywithdrawn from the head, thus locking the needle and thereafter ifgasolen e is removed, or added to the tank, such fact may be readilyproven by inserting the releasing devise in the hole 10 far enough toopen the spring, thus releasing the needle, which will, in case anychange of gasolene has taken place, turn to the position occupied by themagnet. So also, if one is touring and wishes to know the quantity ofgasolene used between one village and another, it is only necessary towithdraw the releasing device, as in Fig. 5, permitting .the lockingdevice to lock the needle, and

when the next place is reached the movement of the releasing device fromthe position shown in Fig. 5 into the position shown in Fig. 6 willimmediately release the needle, letting it turn to the position thenoccupied by the magnet and the distance over which the needle is movedon the dial will indicate the quantity of gasolene used from one to theother place.

This invention is not limited to the particular shape of the releasingdevise as the same may be made in any shape in which keys of Yale andother locks are usually made.

Having described my invention, what I claim as new and desire to secureby Letters Patent is l. A fluid gage comprising a head, a pivotallymounted magnet, a float, operative connections between said float andthe magnet whereby the position of the magnet is determined by the fluidlevel, an indicating magnetic needle revoluble at times in unison withfloat induced movement of said magnet, means to sustain the needle inthe head, and means rendered operative at will to temporarily lock theneedle and restrain it from revoluble movement, the magnet remainingfree atall times to change its position in accordance with variations inthe fluid level.

2. A fluid gage comprising a head, a pivotally mounted magnet, a float,operative connections between said float and the magnet whereby theposition of the magnet is determined by the fluid level, an indicatingmagnetic needle revoluble at times in unison with float induced movementof said magnet, means to sustain the needle in the head, needle lockingmeans operative to lock and restrain the revoluble movement of theneedle, and a releasing device to render the needle-locking meansinoperative in order that theneedle may follow the movement of themagnet.

3. A fluid gage comprising a head, a pivotally mounted magnet, a float,operative connections between said float and magnet whereby the magnetis turned by the movement of the float, a detachable needle carrierhaving a dial, an indicating magnetic needle revoluble over said dial bythe influence of said magnet, and means automatically rendered operativeto lock the needle in said carrier on detaching the carrier from thehead. i

4. A fluid gage comprising a head, a pivotally mounted magnet, a float,operative connections between said float and magnet whereby said magnetis turned by the move-" ment of the float, a detachable needle carrierhaving a dial, an indicating magnetic needle revoluble over said dial bythe influence of said magnet, means to lock the needle in said carrier,and a releasing device sustained by said head and operative to renderthe locking device inoperative when the carrier is sustained by saidhead.

5. In a fluid gage, a removable needle carrier provided with a magneticneedle,-and a combined with a gage head having a stud, a

magnet, and means including a float controlled by a fluid to turn themagnet more or less, said stud serving to render the locking deviceinoperative to lock the needle after the needle carrier has been appliedto said head.

7 In a fluid gage, a needle carrier having a needle pivot, and a lockingdevice comprising. spring arms, combined with a needle having a tubularshank to surround said pivot, the arms of the lockin device normallyclosing upon and em racing said shank and preventing the rotation ofsaid needle on its pivot, and a needle releasing device adapted wheninterposed between the arms to spread them and free the shank.

8. In a fluid gage, a head, a magnet, and means to rotate said magnet insaid head, combined with a needle carrier having a dial, a magneticneedle above the dial, a pivot for said needle, and a locking devicelocated within the needle carrier below said dial, said needle having ashank extended into the space below said dial, the locking device whenoperative acting directly on the shank of the magnetic needle extendedbelow the dial to restrain the rotation of said needle.

9. In a fluid gage, a head, a magnet, and means to rotate said magnet,combined with a fixed, centrally apertured dial, a magnetic needlerevoluble above the dial by the influence of the mzwnet and having atubular shank extended loosely through said dial, a fixed pivot for theneedle, locking means located below the dial and cooperating With the deending needle shank to restrain rotation 0' the needle, and a releasingdevice to cooperate with and render the locking means inoperative.

10. In a fluid gage, a head, a magnet, and means to rotate said magnet,combined with a fixed dial, a magnetic needle revoluble adjacent theretoby the influence of the magnet, a locking device for the needle, and acarrier for said needle dial, and locking device, detachably mounted onthe head, th

locking device being automatically rendered operative to lock the needlein the carrier 011 detaching the carrier from the head, and means torender the locking device inoperative when the carrier is sustained bythe head.

In testimony whereof, I have signed my name to this specification, inthepresence of two subscribing Witnesses.

MORRIS MARTIN. Witnesses:

Gno. W. GREGORY, EVANGELINE 0. BROWN.

